Core matchmaking is based on your player rank and you start your way at level 20 and aim to reach level 1. If you are playing solo, you will be matched with 3 other similarly ranked players although with ranks being reset each month; you may see a level 20 player but they may have just started from scratch again but are a really good team player who has been rank 1 many times before. You can also play with friends (Survive With Friends) which welcomes all ranks. This is a game that really encourages teamwork and every match can play out drastically different which is great and makes ranking up more challenging. You really have to think on your feet and have good awareness. A good team aims to get generators done quickly and if players are hooked; they try and save them as best they can whilst trying not to comrpomise their own saftey in the process. Timing and players working in sync is key as matches can easily have a domino effect where one player gets caught and then others also get impacted and this means gens aren't being done. Matches can last from 7 minutes to over half hour. As points matter; players will do their utmost best to help others and from experience; it's one of the best co-op experiences going where everybody of any ability can play a crucial part.
It's pure fun but with competitive and teamwork elements; for such a basic concept; it does go really deep which makes it such an ingenious game.
Developers work on the game round the clock and they are always balancing and improving the game. Major updates (chapters) happen every 6 months or so which see a new killer, new perks, new map and new add-ons. Funnily enough the new killer from the Saw movies was released yesterday